In July, the government announced the creation of nine new unitary authorities, scrapping 35 smaller councils, with the aim of saving £150m a year.

Unison, which represents about 860,000 local council workers, said the reorganisation would be a “huge undertaking”.

Councils have said the number of likely redundancies will range from a handful at some authorities to a couple of hundred at others. But unions fear these figures are underestimated and want a “clear national framework” of terms and conditions.

However, the Public Sector People Managers’ Association (PPMA) said councils should have the freedom to develop local protocols to deal with the restructuring.

Brendon Hills, head of HR and development at Shropshire County Council, and PPMA lead officer on reorganisation, said: “There will need to be some guidance from central government that takes account of the needs of staff going through transfers. But local authorities need to be able to develop approaches [to transition the arrangements] for themselves.”

These would include HR policies and conditions of service, employee communications and recruitment and retention procedures, Hills added.